3.
INTRODUCTION TO LINUXINTRODUCTION TO LINUX
• Linux is quite possibly the most important freeLinux is quite possibly the most important free
software achievement.software achievement.
• It has been developed into an operating systemIt has been developed into an operating system
for business, education and personalfor business, education and personal
productivity.productivity.
• Linux (pronounced with a short I, as in LIH-Linux (pronounced with a short I, as in LIH-
nucks) is a UNIX operating system clone.nucks) is a UNIX operating system clone.

4.
History of LinuxHistory of Linux
• UNIX is one of the most popular operating systemsUNIX is one of the most popular operating systems
worldwide because of its large support base andworldwide because of its large support base and
distribution.distribution.
• It was originally developed at AT&T as a multitaskingIt was originally developed at AT&T as a multitasking
operating system for minicomputers and mainframes inoperating system for minicomputers and mainframes in
the 1970’s, but has since grown to become one of thethe 1970’s, but has since grown to become one of the
most widely used operating systems.most widely used operating systems.
• Linux is a free version of UNIX developed by LINUSLinux is a free version of UNIX developed by LINUS
TORVALDS at the university of Helsinki in Finland.TORVALDS at the university of Helsinki in Finland.

5.
About LinuxAbout Linux
• Linus Torvalds originally developed Linux as aLinus Torvalds originally developed Linux as a
hobby project.hobby project.
• Minix, a small UNIX system developed byMinix, a small UNIX system developed by
Andy Tanenbaum, inspired itAndy Tanenbaum, inspired it
• The Linux kernel uses no code from AT&T orThe Linux kernel uses no code from AT&T or
any other proprietary source.any other proprietary source.
• On October 5, 1991, Linus announced the firstOn October 5, 1991, Linus announced the first
“official” version of Linux ,which was version“official” version of Linux ,which was version
0.02.0.02.

7.
Why Linux?Why Linux?
• Linux is a UNIX like operating systemsLinux is a UNIX like operating systems
• Multi-user, Multi-tasking and Multi ProcessorMulti-user, Multi-tasking and Multi Processor
SupportSupport
• There are no royalty or license feesThere are no royalty or license fees
““ A Linux Distribution has thousands ofA Linux Distribution has thousands of
dollars worth of software for no cost or a coupledollars worth of software for no cost or a couple
of dollars if purchased on CD/DVD “of dollars if purchased on CD/DVD “

8.
• Software Development SupportsSoftware Development Supports
• Linux runs on nearly any CPULinux runs on nearly any CPU
• Linux works very well as a personal computerLinux works very well as a personal computer
UNIX for the desktopUNIX for the desktop
• Linux works well for server operationsLinux works well for server operations
• X-Window system (An excellent window systemX-Window system (An excellent window system
called X)called X)

12.
• Hardware Devices :Hardware Devices :
The lower most layer is the hardware componentsThe lower most layer is the hardware components
(i.e. physical components like your motherboard, hard disk drive,(i.e. physical components like your motherboard, hard disk drive,
floppy drive, memory, etc…)floppy drive, memory, etc…)
• Kernel :Kernel :
When your system is booted, the Linux kernel willWhen your system is booted, the Linux kernel will
be loaded into the memory of your system and after that thebe loaded into the memory of your system and after that the
kernel will control the entire operating system.kernel will control the entire operating system.
• Shell :Shell :
Shell is an interpreter through which a user canShell is an interpreter through which a user can
interact with kernel.interact with kernel.
Shell is program or command.Shell is program or command.
An application program may be a image editor,An application program may be a image editor,
word processor, music player, Games, and etc…..word processor, music player, Games, and etc…..

15.
Cat CommandCat Command
it’s used to one of the file creation and right now give some content.it’s used to one of the file creation and right now give some content.
• To Create a fileTo Create a file
# cat >murali# cat >murali
welcome towelcome to
accel it academyaccel it academy
^D^D
• To add a ContentTo add a Content
# cat >>murali# cat >>murali
VadapalaniVadapalani
^D^D
• To view the content in a fileTo view the content in a file
# cat murali# cat murali
welcome towelcome to
Accel it academyAccel it academy
VadapalaniVadapalani
##

17.
• Esc a – Curser move the next position switch to insert mode.Esc a – Curser move the next position switch to insert mode.
• Esc i – Curser move to the beginning of the line and switch to insert mode.Esc i – Curser move to the beginning of the line and switch to insert mode.
• Esc A – Curser move to the end of the line and switch to insert mode.Esc A – Curser move to the end of the line and switch to insert mode.
• Esc o – Insert the new line below the curser position and switch to insert mode.Esc o – Insert the new line below the curser position and switch to insert mode.
• Esc O – Insert the new line above the curser position and switch to insert mode.Esc O – Insert the new line above the curser position and switch to insert mode.
• Esc r – Replace the single character.Esc r – Replace the single character.
• Esc R – Replace the enter line after the curser positionEsc R – Replace the enter line after the curser position
• Esc s – Deleted current character and switch to insert mode.Esc s – Deleted current character and switch to insert mode.
• Esc S – Deleted the enter lineEsc S – Deleted the enter line
• Esc x – To delete a character.Esc x – To delete a character.
Esc kEsc k
Esc h Esc lEsc h Esc l
Esc gEsc g
• Esc gg – Move the curser to beginning of the first line.Esc gg – Move the curser to beginning of the first line.
• Esc GG – Move the curser to the beginning of the lost line.Esc GG – Move the curser to the beginning of the lost line.

19.
• rmdir - To remove the directoryrmdir - To remove the directory
• rm –r - To remove the directoryrm –r - To remove the directory
• rm - To remove the file.rm - To remove the file.
• type cat - To find out the location of the commandtype cat - To find out the location of the command
• file murali - To view the type of filefile murali - To view the type of file
• wc - To view the no, of lines (l) , no, of word (w), no, of characters (c) inwc - To view the no, of lines (l) , no, of word (w), no, of characters (c) in
filefile
• mv - To move the filemv - To move the file
• cp - To copy the file and directorycp - To copy the file and directory
• head - 10 murali – To view the top 10 lines in a filehead - 10 murali – To view the top 10 lines in a file
• tail – 10 murali - To view the bottom 10 lines in a filetail – 10 murali - To view the bottom 10 lines in a file
• sort murali - To saw the order wise in a file ( numerical(-n) and reverse (-r)sort murali - To saw the order wise in a file ( numerical(-n) and reverse (-r)
• grep -To search for the stringgrep -To search for the string
• aspell –c murali – To check the correct content in a fileaspell –c murali – To check the correct content in a file
• hostname murali – To change the hostname in muralihostname murali – To change the hostname in murali
• exit -To logout M/Cexit -To logout M/C
• logout - To logout M/Clogout - To logout M/C
• clear - To clear the screenclear - To clear the screen

20.
• whowho - who logged in to our system currently- who logged in to our system currently
• whoamiwhoami - To show the current user- To show the current user
• ttytty - To show the current terminals- To show the current terminals
• echoecho - To display the typed message- To display the typed message
• wallwall - To send the broadcast message- To send the broadcast message
• WriteWrite - To send the message in particular user- To send the message in particular user
• datedate - To show the date and time- To show the date and time
• calcal - To show the calendar- To show the calendar
• bcbc - Calculator- Calculator